polarity: bonds & molecules · 2019. 10. 29. · bond polarity an unequalsharing of electrons...
TRANSCRIPT
CHEMISTRY 161 – FALL 2019 Dr. Mioy T. Huynh
Polarity: Bonds & MoleculesDR. MIOY T. HUYNHYALE UNIVERSITYCHEMISTRY 161
FALL 2019
www.mioy.org/chem161
CHEMISTRY 161 – FALL 2019 Dr. Mioy T. Huynh
Same trend as ionization energy (IE)!
EN decreases down a column.EN increases across a row.
ELECTRONEGATIVITY (EN)The ability for an atom to attract electrons to itself.
CHEMISTRY 161 – FALL 2019 Dr. Mioy T. Huynh
Same trend as ionization energy (IE)!
EN decreases down a column.EN increases across a row.
ELECTRONEGATIVITY (EN)The ability for an atom to attract electrons to itself.
BOND POLARITYAn unequal sharing of electrons in a bond when difference in EN is large.
CHEMISTRY 161 – FALL 2019 Dr. Mioy T. Huynh
Which is the most polar bond type?
C−Se
C=O
Cl−Br
O=O
N−H
C−H
BOND POLARITYAn unequal sharing of electrons in a bond when difference in EN
(ΔEN) is large.
CHEMISTRY 161 – FALL 2019 Dr. Mioy T. Huynh
Which is the most polar bond type?
C−Se ΔEN = 2.5 – 2.4 = 0.1
C=O
Cl−Br
O=O
N−H
C−H
BOND POLARITYAn unequal sharing of electrons in a bond when difference in EN
(ΔEN) is large.
CHEMISTRY 161 – FALL 2019 Dr. Mioy T. Huynh
Which is the most polar bond type?
C−Se ΔEN = 2.5 – 2.4 = 0.1
C=O ΔEN = 3.5 – 2.5 = 1.0
Cl−Br
O=O
N−H
C−H
BOND POLARITYAn unequal sharing of electrons in a bond when difference in EN
(ΔEN) is large.
CHEMISTRY 161 – FALL 2019 Dr. Mioy T. Huynh
Which is the most polar bond type?
C−Se ΔEN = 2.5 – 2.4 = 0.1
C=O ΔEN = 3.5 – 2.5 = 1.0
Cl−Br ΔEN = 3.0 – 2.8 = 0.2
O=O ΔEN = 3.5 – 3.5 = 0.0
N−H ΔEN = 3.0 – 2.1 = 0.9
C−H ΔEN = 2.5 – 2.1 = 0.4
BOND POLARITYAn unequal sharing of electrons in a bond when difference in EN
(ΔEN) is large.
CHEMISTRY 161 – FALL 2019 Dr. Mioy T. Huynh
Which is the most polar bond type?
C−Se ΔEN = 2.5 – 2.4 = 0.1
C=O ΔEN = 3.5 – 2.5 = 1.0
Cl−Br ΔEN = 3.0 – 2.8 = 0.2
O=O ΔEN = 3.5 – 3.5 = 0.0
N−H ΔEN = 3.0 – 2.1 = 0.9
C−H ΔEN = 2.5 – 2.1 = 0.4
BOND POLARITYAn unequal sharing of electrons in a bond when difference in EN
(ΔEN) is large.
CHEMISTRY 161 – FALL 2019 Dr. Mioy T. Huynh
Which is the least polar bond type?
C−Se ΔEN = 2.5 – 2.4 = 0.1
C=O ΔEN = 3.5 – 2.5 = 1.0
Cl−Br ΔEN = 3.0 – 2.8 = 0.2
O=O ΔEN = 3.5 – 3.5 = 0.0
N−H ΔEN = 3.0 – 2.1 = 0.9
C−H ΔEN = 2.5 – 2.1 = 0.4
BOND POLARITYAn unequal sharing of electrons in a bond when difference in EN
(ΔEN) is large.
CHEMISTRY 161 – FALL 2019 Dr. Mioy T. Huynh
Which is the least polar bond type?
C−Se ΔEN = 2.5 – 2.4 = 0.1
C=O ΔEN = 3.5 – 2.5 = 1.0
Cl−Br ΔEN = 3.0 – 2.8 = 0.2
O=O ΔEN = 3.5 – 3.5 = 0.0
N−H ΔEN = 3.0 – 2.1 = 0.9
C−H ΔEN = 2.5 – 2.1 = 0.4
BOND POLARITYAn unequal sharing of electrons in a bond when difference in EN
(ΔEN) is large.
CHEMISTRY 161 – FALL 2019 Dr. Mioy T. Huynh
Draw the bond dipole for each:
C−Se ΔEN = 2.5 – 2.4 = 0.1
C=O ΔEN = 3.5 – 2.5 = 1.0
Cl−Br ΔEN = 3.0 – 2.8 = 0.2
O=O ΔEN = 3.5 – 3.5 = 0.0
N−H ΔEN = 3.0 – 2.1 = 0.9
C−H ΔEN = 2.5 – 2.1 = 0.4
BOND POLARITYAn unequal sharing of electrons in a bond when difference in EN
(ΔEN) is large.
CHEMISTRY 161 – FALL 2019 Dr. Mioy T. Huynh
Draw the bond dipole for each:
C−Se ΔEN = 2.5 – 2.4 = 0.1
C=O ΔEN = 3.5 – 2.5 = 1.0
Cl−Br ΔEN = 3.0 – 2.8 = 0.2
O=O ΔEN = 3.5 – 3.5 = 0.0
N−H ΔEN = 3.0 – 2.1 = 0.9
C−H ΔEN = 2.5 – 2.1 = 0.4
BOND POLARITYAn unequal sharing of electrons in a bond when difference in EN
(ΔEN) is large.
BOND DIPOLEAn arrow pointing from the less
EN to the more EN atom.
CHEMISTRY 161 – FALL 2019 Dr. Mioy T. Huynh
Draw the bond dipole for each:
C−Se ΔEN = 2.5 – 2.4 = 0.1
C=O ΔEN = 3.5 – 2.5 = 1.0
Cl−Br ΔEN = 3.0 – 2.8 = 0.2
O=O ΔEN = 3.5 – 3.5 = 0.0
N−H ΔEN = 3.0 – 2.1 = 0.9
C−H ΔEN = 2.5 – 2.1 = 0.4
BOND POLARITYAn unequal sharing of electrons in a bond when difference in EN
(ΔEN) is large.
BOND DIPOLEAn arrow pointing from the less
EN to the more EN atom.
no bond dipole (nonpolar)
CHEMISTRY 161 – FALL 2019 Dr. Mioy T. Huynh
Draw the bond dipoles for water:
BOND POLARITYAn unequal sharing of electrons in a bond when difference in EN
(ΔEN) is large.
BOND DIPOLEAn arrow pointing from the less
EN to the more EN atom.
CHEMISTRY 161 – FALL 2019 Dr. Mioy T. Huynh
Draw the bond dipoles for water:
Use the molecular geometry not the Lewis structure!
BOND POLARITYAn unequal sharing of electrons in a bond when difference in EN
(ΔEN) is large.
BOND DIPOLEAn arrow pointing from the less
EN to the more EN atom.
CHEMISTRY 161 – FALL 2019 Dr. Mioy T. Huynh
Draw the bond dipoles for water:
Use the molecular geometry not the Lewis structure!
BOND POLARITYAn unequal sharing of electrons in a bond when difference in EN
(ΔEN) is large.
BOND DIPOLEAn arrow pointing from the less
EN to the more EN atom.
CHEMISTRY 161 – FALL 2019 Dr. Mioy T. Huynh
Draw the bond dipoles for water:
Use the molecular geometry not the Lewis structure!
Is water polar?
BOND POLARITYAn unequal sharing of electrons in a bond when difference in EN
(ΔEN) is large.
BOND DIPOLEAn arrow pointing from the less
EN to the more EN atom.
CHEMISTRY 161 – FALL 2019 Dr. Mioy T. Huynh
Draw the bond dipoles for water:
Use the molecular geometry not the Lewis structure!
Is water polar?
BOND POLARITYAn unequal sharing of electrons in a bond when difference in EN
(ΔEN) is large.
BOND DIPOLEAn arrow pointing from the less
EN to the more EN atom.
POLARITY & MOLECULAR DIPOLEThe sum of the bond dipoles in a molecule determines if it is polar.
CHEMISTRY 161 – FALL 2019 Dr. Mioy T. Huynh
Draw the bond dipoles for water:
Use the molecular geometry not the Lewis structure!
Is water polar? YES!
BOND POLARITYAn unequal sharing of electrons in a bond when difference in EN
(ΔEN) is large.
BOND DIPOLEAn arrow pointing from the less
EN to the more EN atom.
POLARITY & MOLECULAR DIPOLEThe sum of the bond dipoles in a molecule determines if it is polar.
CHEMISTRY 161 – FALL 2019 Dr. Mioy T. Huynh
For each, draw the bond dipoles:
SF4 H2O CH4
SN = 5, see-saw SN = 4, bent SN = 4, tetrahedral
CO2 SO2 CH2Cl2
SN = 2, linear SN = 3, bent SN = 4, tetrahedral
CHEMISTRY 161 – FALL 2019 Dr. Mioy T. Huynh
For each, draw the bond dipoles:
SF4 H2O CH4
SN = 5, see-saw SN = 4, bent SN = 4, tetrahedral
CO2 SO2 CH2Cl2
SN = 2, linear SN = 3, bent SN = 4, tetrahedral
CHEMISTRY 161 – FALL 2019 Dr. Mioy T. Huynh
For each, draw the bond dipoles:
SF4 H2O CH4
SN = 5, see-saw SN = 4, bent SN = 4, tetrahedral
CO2 SO2 CH2Cl2
SN = 2, linear SN = 3, bent SN = 4, tetrahedral
CHEMISTRY 161 – FALL 2019 Dr. Mioy T. Huynh
For each, draw the bond dipoles:
SF4 H2O CH4
SN = 5, see-saw SN = 4, bent SN = 4, tetrahedral
CO2 SO2 CH2Cl2
SN = 2, linear SN = 3, bent SN = 4, tetrahedral
CHEMISTRY 161 – FALL 2019 Dr. Mioy T. Huynh
For each, draw the bond dipoles:
SF4 H2O CH4
SN = 5, see-saw SN = 4, bent SN = 4, tetrahedral
CO2 SO2 CH2Cl2
SN = 2, linear SN = 3, bent SN = 4, tetrahedral
CHEMISTRY 161 – FALL 2019 Dr. Mioy T. Huynh
For each, draw the bond dipoles:
SF4 H2O CH4
SN = 5, see-saw SN = 4, bent SN = 4, tetrahedral
CO2 SO2 CH2Cl2
SN = 2, linear SN = 3, bent SN = 4, tetrahedral
CHEMISTRY 161 – FALL 2019 Dr. Mioy T. Huynh
For each, determine if polar and draw the molecular dipoles:
SF4 H2O CH4
SN = 5, see-saw SN = 4, bent SN = 4, tetrahedral
CO2 SO2 CH2Cl2
SN = 2, linear SN = 3, bent SN = 4, tetrahedral
POLAR
CHEMISTRY 161 – FALL 2019 Dr. Mioy T. Huynh
For each, determine if polar and draw the molecular dipoles:
SF4 H2O CH4
SN = 5, see-saw SN = 4, bent SN = 4, tetrahedral
CO2 SO2 CH2Cl2
SN = 2, linear SN = 3, bent SN = 4, tetrahedral
POLAR POLAR
CHEMISTRY 161 – FALL 2019 Dr. Mioy T. Huynh
For each, determine if polar and draw the molecular dipoles:
SF4 H2O CH4
SN = 5, see-saw SN = 4, bent SN = 4, tetrahedral
CO2 SO2 CH2Cl2
SN = 2, linear SN = 3, bent SN = 4, tetrahedral
POLAR POLAR NONPOLAR
CHEMISTRY 161 – FALL 2019 Dr. Mioy T. Huynh
For each, determine if polar and draw the molecular dipoles:
SF4 H2O CH4
SN = 5, see-saw SN = 4, bent SN = 4, tetrahedral
CO2 SO2 CH2Cl2
SN = 2, linear SN = 3, bent SN = 4, tetrahedral
POLAR POLAR NONPOLAR
NONPOLAR
CHEMISTRY 161 – FALL 2019 Dr. Mioy T. Huynh
For each, determine if polar and draw the molecular dipoles:
SF4 H2O CH4
SN = 5, see-saw SN = 4, bent SN = 4, tetrahedral
CO2 SO2 CH2Cl2
SN = 2, linear SN = 3, bent SN = 4, tetrahedral
POLAR POLAR NONPOLAR
NONPOLAR POLAR
CHEMISTRY 161 – FALL 2019 Dr. Mioy T. Huynh
For each, determine if polar and draw the molecular dipoles:
SF4 H2O CH4
SN = 5, see-saw SN = 4, bent SN = 4, tetrahedral
CO2 SO2 CH2Cl2
SN = 2, linear SN = 3, bent SN = 4, tetrahedral
POLAR POLAR NONPOLAR
NONPOLAR POLAR POLAR